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How is dyslexia diagnosed?

What should I be looking for in an assessor when seeking a dyslexia diagnosis?

It is important when booking a diagnostic assessment for dyslexia to ensure that the assessment is carried out by a professional who is suitably qualified. For those who are not booking an assessment through an organisation such as the British Dyslexia Association, this is even more important to bear in mind to ensure that your assessment and report are of the appropriate standard. Below is guidance for those seeking a diagnostic assessment with a specialist teacher or other professional.

There are two types of assessor:

  • Specialist Teacher
  • Educational Psychologist

With regard to a specialist teacher, the British Dyslexia Association recommend individuals seeking an assessment, or their families, engage an assessor who has:

  • Active AMBDA: an AMBDA accreditation together with evidence that they have updated their CPD within the last three years
  • An Assessment Practising Certificate (APC)

What do these terms mean and how can I check that an assessor has these?

AMBDA stands for Associate Member of the British Dyslexia Association and this indicates a high standard of professional competence in both diagnostic assessment and teaching.

Those who hold AMBDA have completed a BDA approved course to gain their level 7 qualification. This will have included extensive supervised specialist teaching and report writing. AMBDA holders are expected to commit to continuing professional development and submit a portfolio to the BDA for verification every three years – we refer to this as ‘active AMBDA’.

To check if an assessor has active AMBDA, it is advisable to ask them for a copy of their most recent AMBDA certificate, which will state the date that it was issued. This would need to be within the last three years.

Assessors with a level 7, may alternatively hold professional membership of PATOSS or The Dyslexia Guild. Individuals would need to ask the assessor for evidence of membership of PATOSS or The Dyslexia Guild.

Assessment Practising Certificate (APC)

An APC recognises professional achievement at postgraduate level as well as a commitment to Continuing Professional Development (CPD) solely in relation to assessment (not specialist teaching). Assessment Practising Certificates are renewed every three years through an APC awarding body by providing evidence of report writing practice which meets appropriate guidelines and evidence of relevant Continuing Professional Development. After three submissions, assessors are not required to submit a report, only CPD.

The APC must be current and will have been issued by a SASC (SPLD Assessment Standards Committee) approved professional association. There are currently three APC awarding bodies:

  • British Dyslexia Association
  • Dyslexia Guild

To determine if someone has a current APC, it is advisable to ask them for a copy of their most recent APC certificate, which will state the date that it was issued. This would need to be within the last three years. A list of APC holders can also be found at:

Disabled Student’s Allowance:

Please note that if a report is to be used as evidence to apply for Disabled Student’s Allowance, the assessor must have a current APC at the time of completing the assessment and writing the report.


Where an educational psychologist is carrying out the assessment they must be registered the Health and Care Professions Council (HCPC) (

Other factors to consider:

  • All assessors should have an enhanced DBS clearance. DBS stands for Disclosure and Barring Service, which is the public body that carries out DBS checks. More information on what is checked for in an enhanced DBS can be found here:
  • All assessors should also hold Professional Indemnity Insurance.

Individuals can check that an assessor has these by asking to see copies of each document.

The benefits of choosing a BDA Approved Assessor

All BDA assessors are checked to ensure that they all hold the above qualifications. In addition, BDA assessors are all subject to our own rigorous Quality Assurance processes to make sure that they are operating to the highest levels of professional standards and undertake regular CPD. They are required to submit an initial report for approval before starting work with us and then reports are reviewed on a regular basis to ensure that standards remain high.

We hope that this guidance supports you to choose the best assessor for you or your child.